window/app aware bindkey/input control application?

[Chris Telting]

Sorry don't have the necessary words to describe what I want.

I'm wondering if there exists an app or set of apps that are 
window/application aware for use in conjunction with multimedia keys, 
remote control, input control surfaces.

Simple example: detect all mutimedia applications, if only one or none 
is started then issue command1 otherwise see if any of the above 
applications has the focus and issue it's appropriate command else play 
an error sound.

I guess you could say I'm interested in scripting keyboard input in 
conjunction with the window manager.